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LED Resistor

Calculate LED Resistor instantly with the exact formula and a worked example. Free online calculator — no signup, works on mobile.

LED Resistor

Supply voltageV
U LEDV
LED currentmA
Resistor
150Ω
R = (Vs−Vled) / ICalculate LED Resistor instantly with the exact formula and a worked example. Free online calculator — no signup, works on mobile.

More about: LED Resistor

What it calculates

The “LED Resistor” calculator computes Resistor in Ω from 3 parameters: supply voltage (V), u led (V), led current (mA).

A standard physics formula used in educational and engineering tasks.

Example calculation

With parameters Supply voltage = 5 V, U LED = 2 V, LED current = 20 mA the result is 150 Ω (R = (Vs−Vled) / I).

How to use

  1. Enter the parameter values — every field above is adjustable with a slider.
  2. The result and related metrics are calculated automatically as you type.
  3. Use the additional metrics shown (if any) where needed.
  4. Copy the result or bookmark the page.

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